Assessment of the calendar aging of lithium-ion batteries for a long-term—Space missions

Energy availability is a critical challenge for space missions, especially for those missions designed to last many decades. Space satellites have depended on various combinations of radioisotope thermoelectric generators (RGTs), solar arrays, and batteries for power. For deep space missions lasting as long as 50 + years, batteries will also be needed for applications when there is no sunlight and RTGs cannot support peak power demand due to their insufficient specific power. This paper addresses the potential use of lithium-ion batteries for long-term space missions. Using data collected from the literature and internal experiments, a calendar aging model is developed to assess the capacity fade as a function of temperature, state-of-charge and time. The results for various LIB chemistries are used to identify the best candidate chemistries and determine the conditions, with a focus on low temperatures, that can best enable deep space missions

Lithium-Ion Batteries

Lithium-ion batteries (LIBs), as a key part of the 2019 Nobel Prize in Chemistry, have become increasingly important in recent years, owing to their potential impact on building a more sustainable future. Compared with other batteries developed, LIBs offer high energy density, high discharge power, and a long service life. These characteristics have facilitated a remarkable advance of LIBs in many frontiers, including electric vehicles, portable and flexible electronics, and stationary applications. Since the field of LIBs is advancing rapidly and attracting an increasing number of researchers, it is necessary to often provide the community with the latest updates. Therefore, this book was designed to focus on updating the electrochemical community with the latest advances and prospects on various aspects of LIBs. The materials presented in this book cover advances in several fronts of the technology, ranging from detailed fundamental studies of the electrochemical cell to investigations to better improve parameters related to battery packs

Control of Energy Storage

Energy storage can provide numerous beneficial services and cost savings within the electricity grid, especially when facing future challenges like renewable and electric vehicle (EV) integration. Public bodies, private companies and individuals are deploying storage facilities for several purposes, including arbitrage, grid support, renewable generation, and demand-side management. Storage deployment can therefore yield benefits like reduced frequency fluctuation, better asset utilisation and more predictable power profiles. Such uses of energy storage can reduce the cost of energy, reduce the strain on the grid, reduce the environmental impact of energy use, and prepare the network for future challenges. This Special Issue of Energies explore the latest developments in the control of energy storage in support of the wider energy network, and focus on the control of storage rather than the storage technology itself

Development of Hybrid Fuel Cell / Li-ion Battery Systems

Electrochemical power systems are needed to de-carbonise the transport industry. Fuel cells and battery systems alone may not be able to meet the diverse set of requirements, but when hybridised, their applicability to this sector is vastly increased. This raises questions around the specific nature of hybridisation. This thesis aims to expand our understanding of fuel cell and lithium-ion battery hybridisation for automotive applications, through a combined experimental and computational approach. Prior to undertaking such research, an understanding of each individual system is required. This is perused along the themes of current heterogeneity, and applied to parallel battery cells in two common electrical configurations and across the active area of a 100 cm2 polymer exchange fuel cell. First, it is shown the electrical configuration of the parallel string has significant impact on the current distribution, impacting the charge throughput of each cell and the usable capacity of the module. Degradation modelling showed the lifetime of the module is reduced by 4.5% in the less optimal configuration. Secondly, the current and thermal distribution within a fuel cell is investigated for a range of operating conditions such as flooding, drying and cold start. Electrochemical impedance spectroscopy is used to understand the conditions of the membrane and reactant time constants in-situ. Results indicate how the design of fuel cells can be refined to improve performance in challenging operating conditions. Finally, the investigation of electrical and thermal hybridisation is conducted on a passenger sized vehicle. A common modelling framework is developed, using the models developed in the fuel cell and battery chapters, to assess electrical energy management systems. A novel fuzzy logic controller is developed which mutates the output membership functions based on the ‘state-of-degradation’, a parameter derived from an interconnected electrochemical surface area loss and system state model. The controller is able to extend the lifetime of the fuel cell by 32.8% in its presented configuration. The common framework is then developed to include dynamic thermal models of the fuel cell, battery pack, radiator and auxiliaries to investigate whether combining the battery pack and fuel cell stack onto a single coolant loop is feasible. The system is tested against a range of operating conditions and its performance is discussed. These findings are expected to aid the transport industry in the transition to a zero emission future

A Positive Ion Beamline for Space Qualification of Birefringent Materials

The constant advancements in spaceborne technology have provided an immense increase to the boundaries of human knowledge in a variety of research fields. As these continue, and new technologies arise, their suitability for deployment in the space environment must be assessed due to the harsh operating environment of space. One component of the space environment is intense radiation, specifically charged particle radiation, which can cause damage to a variety of system components. Effects include changes to electrical, structural, and optical properties, the latter of which is the focus of this work. A recently introduced technology to spaceborne imaging instrumentation is Acousto-Optic Tunable Filters. These devices use the Acousto-Optic effect and birefringent materials, such as tellurium dioxide and lithium niobate, to create narrow band image quality tunable filters. As common radiation damage effects include changes to transmittance, reflectance and absorbance of optical materials, as well as changes to the atomic structure causing changes to refractive indices and birefringence, radiation testing of these devices to assess long term performance is critical to further development of the technology for space applications. Radiation testing involves accelerated lifetime testing of materials under multiple years' worth of equivalent radiation in much shorter time frames (hours), using charged particle radiation provided by an ion accelerator. This work details the development of a positive ion accelerator and its use for radiation testing. The accelerator can provide beam energies from 5 - 20 keV, beam diameters of 0.8 - 2.5 cm and beam currents from 0.5 - 15 $\mu$A, all adjustable by user input settings. The system can also accommodate other ion species such as helium ions. The system was primarily used with proton radiation, due to its dominance in the solar wind and general space environment, to examine induced damage effects in silicon, quartz, lithium niobate and tellurium dioxide as a function of fluence (protons/$\text{cm}^2$). Measurements of transmittance, reflectance and absorbance, as well as an investigation with Raman spectroscopy, were completed for all materials at varying fluences. Comparison of results to those in the literature shows good agreement, however, not all results have comparable data available in the current literature. Results are used to assess space mission suitability and show that tellurium dioxide has the highest radiation resistance of the investigated materials

How to Recognize and Control Interfacial Phenomena That Hinder the Advancement of Clean Energy Technologies

Nuclear energy and electrochemical energy storage, such as batteries, are key parts to the clean energy transition of critical infrastructure. This work aims to define, monitor, and modify interfacial layers that would improve the utility of materials in harsh environments seen in nuclear and energy storage applications. First, the studying of zirconium alloys, which is used as nuclear cladding, was done to better understand the degradation mechanisms within an extreme environment. High-resolution characterization techniques were used to correlate corrosion mechanisms to equivalent circuit models from novel in-pile electrochemical impedance spectroscopy sensors. Advancement in this sensor technology could provide further insight and monitoring of the complex degradation mechanisms in a harsh nuclear core environment. A novel method was developed to spatially map Raman spectral features throughout the oxide cross-section, revealing a direct correlation between tetragonal zirconia phase and compressive stress, thus supporting the theory of a stress-induced breakaway phenomenon. Additionally, a comparison of interface- and relaxed-tetragonal phase revealed a difference in stabilization mechanisms, where relaxed-tetragonal phase is stabilized solely from sub-stoichiometric contributions. Coupling Raman mapping with elemental analysis via energy dispersive X-ray spectroscopy and scanning Kelvin probe force microscopy led to a distinction of secondary-phase particles and their nobility relative to surrounding zirconium oxide and metal. Lastly, a p-n junction at the tetragonal/monoclinic zirconia interface was observed, supporting the theory that the tetragonal layer at the metal/oxide interface provides an additional barrier to an otherwise diffusion-limited oxidation mechanism. Other interfacial studies were conducted on next-generation battery anodes. High-capacity lithium, deemed the “Holy Grail” of battery materials, undergoes unstable interactions in most, if not all, environments. In a cell, this causes poor cycle life and/or possible safety concerns via dendritic-driven short circuiting. Novel development of lithium-metal batteries was accomplished firstly with a facile design of a closed-host, porous/dense bi-layer interfacial structure formed on lithium through a two-step ex situ/in situ process, only made possible with an electrolyte additive included in the cell. This design prevented dendrite growth, improved interfacial flexibility and ionic conduction when compared to a traditional LiF coating, reduced volume fluctuations, and prevented extensive parasitic reactions. In summary, the works presented here were done in effort to better understand and control interfacial mechanisms in both nuclear energy and energy storage fields

Application of Grating-Based Interferometry to Additive Manufacturing, Lithium-ion Batteries, and Crystals

X-ray and neutron imaging are convenient ways to non-destructively observe novel materials. X-rays provide advantages of low cost and high brilliance while neutrons show bulk and isotopic sensitivity. Imaging provides a way for observing chemical and physical properties of materials without the need for destruction. The way of the imaging future is utilizing imaging with grating-based interferometry. In comparison to traditional radiography and tomography, by using absorption and phase gratings in the beam path, the absorption, phase, and scattering of a sample can be detected. In essence, three image datasets can be obtained in one experiment, saving substantially on costs (especially at expensive neutron facilities), time and materials. With several methods of interferometry available, the focus in this work is Talbot-Lau interferometry and newer designs referred to as near-field and far-field interferometry. X-ray Talbot-Lau interferometry experiments were performed at the LSU synchrotron, Center for Advanced Microstructures and Devices (CAMD), using a microfocus X-ray tube and synchrotron X-rays (38 keV). Neutron Talbot-Lau experiments were performed at the CONRAD2 beamline (HZB, Berlin, Germany) and far-field experiments at the NG6 beamline (NIST, Gaithersburg, USA). Neutron imaging of the additive manufactured samples revealed pore structures and evi- dence of fracture as a function of fatigue. Battery imaging shows the migration of lithium across battery layers on a visual and quantitative level. X-ray and neutron imaging of potentially twinned crystals revealed the importance of preserving data in the 2D projection images that was lost in volume reconstruction. A comparison of Talbot-Lau, near-field, and far-field interferometry with application to additively manufactured samples, lithium-ion batteries, and geometrically twinned crystals is presented

Nanocrystal

We focused on cutting-edge science and technology of Nanocrystals in this book. "Nanocrystal" is expected to lead to the creation of new materials with revolutionary properties and functions. It will open up fresh possibilities for the solution to the environmental problems and energy problems. We wish that this book contributes to bequeath a beautiful environment and valuable resources to subsequent generations